The intradermal test in the diagnosis of bilharziasis.

The diagnosis of bilharziasis by detection of schistosome eggs in the urine or faeces of patients is often not possible in the later stages of the disease, when elimination of the eggs is rendered increasingly difficult. To overcome this difficulty, an immunological test has been developed, based on the cutaneous response to an injection of an antigen prepared from the cercariae, adult worms, eggs or miracidia of Schistosoma.In this paper, the author reviews the various procedures for obtaining the basic material for antigen preparation, describes briefly the method of preparation, outlines the nature and properties of the specific antigens, and discusses the skin-testing procedure, with special reference to the criteria for evaluating the results. He points out that the intradermal test may prove useful in epidemiological surveys as well as in the diagnosis of individual cases.